Acyclovir with the birth control pill
Many women of reproductive age take a combined or progestogen-only oral contraceptive while also using a chronic medication such as Acyclovir (Acyclovir). The combination is generally fine at 200mg, 400mg, 800mg, but a small number of medications can reduce contraceptive efficacy meaningfully and need either a backup method or a switch.
How Acyclovir can affect contraceptive efficacy
Combined and progestogen-only contraceptives are metabolised through CYP3A4. Strong CYP3A4 inducers (some antiepileptics, rifampicin, St John's Wort) lower contraceptive plasma levels and reduce efficacy. Whether Acyclovir acts on CYP3A4 determines whether Acyclovir affects contraception. Most agents in Antiviral Medications have no clinically meaningful effect on the pill at 200mg, 400mg, 800mg.
Practical guidance
According to the prescribing information for Acyclovir, women on hormonal contraception should review Acyclovir with the prescribing pharmacist or doctor. Where an interaction is documented, additional barrier contraception or switching to a non-oral method (IUD, implant) for the duration of Acyclovir therapy is the standard mitigation.
Frequently asked questions
Will Acyclovir make my pill less effective? ▾
Most Antiviral Medications medications at 200mg, 400mg, 800mg do not affect oral contraceptive efficacy. The exceptions are CYP3A4-inducing drugs and a small number of others. The prescribing information for Acyclovir states whether the interaction is meaningful.
Do I need a backup contraceptive on Acyclovir? ▾
Backup contraception is needed only when there is a documented interaction between Acyclovir and the contraceptive method. For most users at 200mg, 400mg, 800mg, no backup is required. The pharmacist confirms whether Acyclovir interacts with hormonal contraception.
More on Acyclovir
- With alcoholAcyclovir and alcohol — is it safe to drink?
- With foodShould Acyclovir be taken with food?
- Side effectsAcyclovir side effects: common, rare and warning signs
- Dosage guideAcyclovir dosage guide: how much to take and when
- OnsetHow fast does Acyclovir start working?
- DurationHow long does Acyclovir last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.